Wireless communication networks enable voice and data services for various mobile electronic devices, such as cellular phones, personal digital assistants, and laptop computers. The increased use of these and many other, electronic devices has resulted in an increased demand for high-speed and reliable wireless communication networks.
FIG. 1 is a diagram illustrating an exemplary wireless communication network 100 for providing wireless services to electronic devices. Network 100 may include a wireless service provider 102, a macro-cell base station (BS) 104, a macro-cell coverage area 106, and first mobile subscriber (MS) 108.
Wireless service provider 102 may provide wireless services, such as voice and data, to electronic devices. To deliver the wireless services, wireless service provider 102 may link to macro-cell BS 104. Macro-cell BS 104 may be a high-power wireless access point that wirelessly connects electronic devices to wireless service provider 102. Macro-cell BS 104 delivers wireless connectivity to electronic devices located within macro-cell coverage area 106. Macro-cell coverage area 106 is a geographic coverage area within a wireless range of macro-cell BS 104. In exemplary network 100, first MS 108 is assumed to be located within macro-cell coverage area 106. First MS 108 may be a mobile phone, a personal digital assistant, or a computer, for example. First MS 108 wirelessly links to macro-cell BS 104 in order to receive voice and data services from wireless service provider 102.
Strength of signals received by macro-cell BS 104 may vary throughout macro-cell coverage area 106. For example, if macro-cell BS 104 is deployed in a city with many buildings, the buildings may obstruct connectivity to macro-cell BS 104 in some areas of macro-cell coverage area 106. Accordingly, connectivity to macro-cell BS 104 may be weak in some areas of macro-cell coverage area 106.
Accordingly, wireless communication network 100 may further include a network 110, a broadband router 112, a femto-cell BS 114, and a femto-cell coverage area 116. A second MS 118 is assumed to be located within femto-cell coverage area 116. Wireless service provider 102 is linked to network 110. Network 110 may include any link or communications network, including the Internet. Network 110 is further linked to broadband router 112. Broadband router 112 provides external connectivity to network 110. Broadband router 112 may be any access point to network 110, such as a dial-up modem, cable modem, DSL modem, wireless modem or the like.
Broadband router 112 is linked to femto-cell BS 114. Femto-cell BS 114 may be a low power wireless access point that wirelessly connects electronic devices to wireless service provider 102, via broadband router 112 and network 110. There may be any number of femto-cell BS's 114 within macro-cell coverage area 106, each such femto-cell BS 114 being capable of delivering wireless connectivity to electronic devices located within femto-cell coverage area 116. Femto-cell coverage area 116 is a geographic coverage area within a wireless range of femto-cell BS 114, and is smaller than macro-cell coverage area 106. Femto-cell coverage area 116 serves to provide overlapping coverage for weak areas of macro-cell coverage area 106 by boosting coverage in weak areas of macro-cell coverage area 106.
Second MS 118 may be a mobile phone, a personal digital assistant, or a computer, for example. Second MS 118 wirelessly links to femto-cell BS 114 in order to receive voice and data services from wireless service provider 102. Therefore, even if second MS 118 is in a weak spot within macro-cell coverage area 106, it may still receive services from wireless service provider 102 by linking to femto-cell BS 114. In this way, femto-cell BS 114 strengthens coverage provided by macro-cell BS 104.
Because second MS 118 may be a mobile electronic device, it may have limited battery power. Accordingly, second MS 118 may enter an idle mode when it is not actively using services provided by wireless service provider 102. For example, second MS 118 may enter the idle mode when it is not connected to a voice call, or when it is not connected to the Internet. When second MS 118 goes into the idle mode, it ceases communicating with femto-cell 114. Moreover, second MS 118 may move to a different coverage area, other than femto-cell coverage area 116 while in the idle mode. Accordingly, it may be difficult for wireless service provider 102 to locate second MS 118 if it moves to a different coverage area while in the idle mode.